Extracellular and intracellular responses of the ganglion nodosum to stimulation of the vagus nerve were recorded. Based on the conduction velocity of these extra and intracellular responses, the ganglionic cells appeared to respond mainly to the impulses initiated from the C-fibers; and, occasionally also from the A-delta fibers of the vagus. Investigation of the electrical properties of the ganglionic cells (e.g., input resistance, capacitance, time constance, change in membrane potentials and discharage activities) in response to electric stimulation of the vagus and superficial peroneal nerves and to application of chemical agents is in process. At present, no conclusive statements can be made.